Objectives: This study aimed to examine feasibility of testing and frequency of abnormal plasma glucose among dental patients in The Dental Practice-Based Research Network. Methods: Eligible dental patients were ≥19 years old and had at least one American Diabetes Association-defined risk factor for diabetes mellitus or an existing diagnosis of diabetes or pre-diabetes. Random (fasting not required) plasma glucose was measured in standardized fashion using a commercial glucometer. Readings <70 or >300 mg/dl triggered re-testing. Patients with glucose ≥126 mg/dl were referred for medical follow-up. Results: Of 498 subjects in 28 dental practices, 491 (98 %) consented and 418 (85.1 %) qualified for testing. Fifty-one patients (12.2 %) had diabetes; 24 (5.7 %) had pre-diabetes. Glucose ranged from 50 to 465 mg/dl. One hundred twenty-nine subjects (31 %) had readings outside the normal range; of these, 28 (6.7 %) had readings <80 mg/dl and 101 (24.2 %) had readings ≥126 mg/dl; in nine patients (seven with diabetes), glucose was >200 mg/dl. Conclusions: A significant proportion of patients tested had abnormal blood glucose. Routine glucose testing in dental practice of populations at risk or diagnosed with diabetes may be beneficial and community dental practices hold promise as settings for diabetes and pre-diabetes screening and monitoring. Clinical relevance: Results suggest that implementation of glucose measurement in dental practice may provide important clinical and health information for both patients and practitioners. © 2012 Springer-Verlag.